Original Research Article Development of solar home systems for home lighting for the base of the pyramid population Boucar Diouf a,⇑ , Ramchandra Pode b,⇑ a Kyung Hee University, Department of Information Display, Dongdaemoon-gu, Seoul 130-701, Republic of Korea b Kyung Hee University, Department of Physics, Dongdaemoon-gu, Seoul 130-701, Republic of Korea article info Article history: Received 28 December 2012 Revised 24 May 2013 Accepted 30 May 2013 Keywords: BoP population Poverty penalty in energy sector Senegal Solar home systems (SHSs) Fee-for services energy delivery model abstract Low level of rural electrification rate is attributed to the high cost of grid expansion combined with the insufficiency of energy resources and lower demand for the energy. Furthermore, populations in rural areas in developing countries are characterized by their low incomes and savings. About 4 billion people live at the base of the pyramid (BoP), having an income of US$1–4/day/person at the local purchasing power parities. Usually, villagers use home lighting for 4–6 h per day and spend about US$5–10 a month on kerosene fuel in most parts of the world. Therefore, the motivation of the present investigation is to provide the modern lighting to rural populations and to replace the currently inefficient and unhealthy kerosene fuel illumination without any addition to the existing expenditure on kerosene fuel based light- ing. We have developed a typical 12 V DC LED (light emitting diode) photovoltaic system and installed in CouréMbatar in Senegal and adopted fee-for services energy delivery model. The concept of LED solar lighting with no additional burden to the current cost of lighting is widely accepted by the villagers and may provide the guidelines for a targeted solution for the rural electrification. Ó 2013 Elsevier Ltd. All rights reserved. Introduction About 1.4 billion people (or roughly 22% of the world’s popula- tion) around the world, most of who have lived in remote areas, still do not have access to the regular electricity [1,2]. The Interna- tional Energy Agency estimates that roughly 85% of the people without electricity live in rural areas in developing countries, mostly in semi-urban or remote rural areas [3]. About 4 billion people live at the base of the pyramid (BoP), having an income of US$1–4/day/person at the local purchasing power parities (PPPs) [4,5]. Prahalad and Hart had introduced the concept of BoP to alleviate the poverty to achieve the human devel- opment [6]. The minimum annual per capita income considered necessary to maintain a decent life is about US$1500. In addition, altogether BoP population represents a market of 5 trillion US$ at the local PPPs which remains untapped by the global multi-na- tional companies [5–7]. The 4 billion BoP populations which in- clude 2.7 billion traditional biomass users and 1.4 billion off-grid people spend US$433 billion/year for the energy services [5]. An average of 9% of the overall BoP household expenditure is spent on energy services including lighting. Households with an annual income of up to US$500 spend an average of US$148 per year on energy, equivalent to around US$00.40 a day. Those earning be- tween US$1000 and 1500 per year spend nearly US$1 a day on en- ergy [8]. A study performed by MicroEnergy International showed that 1 kWh energy from the grid costs about US$2.30 in rural Bangla- desh, compared to about US$0.30 in Western Europe [9]. In 2000, the cost of lighting in Guatemala was about US$0.08 per kWh from the grid, US$5.87 from kerosene and US$13.00 from candles [10]. In 2012, Senegal’s consumer electricity tariff rate was CFA105 per kWh, around US$0.21 from the grid (current conversion rate is 1 US$ = 496 CFA) [11] and CFA250 (around US$0.50) per kWh from biomass power plant in rural Senegal [12]. CFA is the currency of Senegal and meaning is Communauté Financière Africaine (African Financial Community). Indeed, poor people (off-grid population living in villages whose daily income is US$1–4/day/persons) have to spend more for lower quality product or service than wealthier ones. Such populations utilize more percentage of their income on lower quality services and products as compared to urban popula- tions. Off-grid populations in these contexts are therefore well pre- pared to pay affordable sums for clean and reliable energy services. Different business models for delivering solar electricity ser- vices to rural populations (BoP) include cash delivery model, credit delivery model, leasing delivery model, subsidy delivery model, and long term service model [13]. Failure could also take place as it is not possible to make all the BoP businesses profitable. Never- theless, the BoP business model has the potential to alleviate the energy poverty. 2213-1388/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.seta.2013.05.005 ⇑ Corresponding authors. E-mail addresses: diouf@khu.ac.kr (B. Diouf), rbpode@khu.ac.kr (R. Pode). Sustainable Energy Technologies and Assessments 3 (2013) 27–32 Contents lists available at SciVerse ScienceDirect Sustainable Energy Technologies and Assessments journal homepage: www.elsevier.com/locate/seta